Earning point-blank kills or medals in Black Ops Cold War requires a lot of close-quarters speed.
A point-blank kill isn't a special type of kill. Rather, it is a range indicator that many players may be tracking in order to unlock new camos for their weapons.
Some of the weapons that require point-blank kills for camo challenges are in the shotgun class and the submachine gun class. The challenges sound easy, but getting a point-blank kill is much closer than close quarters, hence the name 'point blank'.
Getting to point-blank range in Black Ops Cold War
Black Ops Cold War can be unforgiving, especially if players are taking their time and using a weapon like the AUG. This means that any players attempting to get a point-blank kill shouldn't just be charging at other players when they see them. Some finesse is needed to get to that point-blank range.
One of the best ways to employ some quick finesse with a charge is to play an objective-based game like Domination or Hardpoint. If another player is on the point for those game modes, everyone is notified. Usually, there is only so much space to move in those objectives.
With that info, players can use cover and quick movements like sliding to get inside a point against the other player. In many cases, being inside the point and rushing there will give the opportunity for a clean point-blank kill, especially on a shotgun or submachine gun.
Another method is to do the exact opposite and slow down gameplay. If a player can learn the flow of a map, they can predict where other players are going to be running. This means that they can hunker down somewhere that they know players will run by them without paying as much attention.
It isn't a guaranteed way to get kills, but it will instantly close the gap that is needed in order to land point-blank kills and get those medals. Point blank really doesn't mean a close-quarters kill. It is very literal and requires players to be almost right up on top of another player.
Using stealth methods for point-blank kills in Black Ops Cold War is another option that could close that gap. Regardless of the method, the goal is to be right in the other player's face. Doing that consistently should unlock those camos fairly fast.